Lift roller stand

ABSTRACT

This invention relates to portable hand operated combination lift and roller stands particularly useful in handling long lengths of welded railroad rail into and out of storage. Rollers are mounted on a portion of a shaft eccentric to a drive extension which may be rotated by a hand wrench and which is equipped with a reversible backstop mechanism to safely elevate the heavy rails. The roller shaft is supported in levers pivotally mounted in the base which have freely hanging pawls concentric with the drive extension cooperating with pawl steps in the base to obtain additional height variations.

United States-Patent [56] References Cited UNITED STATES PATENTS P .m rfln mmmE mud J R m m k W 8mm n M a1 9 m W 2 mF I Iw 2 yn Man mM OIMIO. 1rs 3PAA n .m f n m wm 1 ,oe 3H Cm ZQLICJ M m m SMJFS 0. dc N ee mm d P iD um$ AFPA HUM La -47 a corporation of Delaware .f wno mm a w w d n dfnm m m kwrm l u we pc storage. Rollers are mounted on a portion of ashaft eccentric to a drive extension which may be rotated by a handwrench and which is equipped with a reversible bac & n

F N m w r mD nm R mm L1 4 w kstop mechanism shaft is supported whichhave freely [52] U.S. 254/1, to safely elevate the heavy rails, Theroller in levers pivotally mounted in the base hanging pawls concentricwith the drive extension cooperating with paw] steps in the base toobtain additional height variations.

20 12 40 4 31 3 9 9 1 1 M; 1 4 M 2 1 t .1 2 u U 4 n l ".2 M "H mh C r a8 "S m l d Ld mm 1] 0 55 [.l

PATENTED m1 9m:

SHEET 1 BF ,3

INVEN TOR JOHN P RAUSCH BY FE,

ATTY'S PATENTEU JAN] 9 ran SHEET 2 BF 3 m IN INVENTOR JOHN P. RAUSCH BYac? ATTYS PATENTEU mu 9197i sum 3 OF 3 wmnuh l/VVEN TO JOHN P- RAUSCHawf W ATTYS 1 urr ROLLER STAND BACKGROUND OF THE INVENTION 1. Field ofthe Invention This lift roller stand finds use particularly in thehandling of one quarter mile lengths of welded railroad rail which areheavy and hard to handle because of their length. The rails must belifted, lowered and rolled in the various steps involved in moving themfrom the welding equipment into yard storage or out of storage on to thetrack laying train. These small portable units are usually spaced about35 feet apart and, when equipped with tree rollers per unit, cannormally handle the daily output of the rail welding and finishingequipment before shifting is required. Large amounts of labor or thelarge investment required for power operated conveyors or otherequipment in a more automated welding plant are thus avoided.

2. Description of the Prior Art The use of various forms of handoperatedrail lifters and jacks incorporating a toothed sectorcooperating with a pinion together with a ratchet and pawl mechanism toadjust the height of a single rail is old. Units of this type do nothave a low enough silhouette for them to be pushed completely under arail to an adjoining one nor do they have rollers on which the rails maybe moved and, accordingly. they are normally used I beside only onerail.

The use of rollers which are mounted in slots in the floor of a platformortruck body and which may be raised above the floor level to movematerial across the floor more easily is also old. However these arefixed units where portability and ease of changing their location is notrequired The innovation of welding railroad rail into one-quarter milelengths to eliminate the many intermediate joints in using standard 39foot lengths has required new equipment to facilitate handling theselong rails. One method has utilized a special train in which the welderand grinding equipment is mounted on one car. A power operated pusherthen pushes the completed rail through multiroller, multilayer A framestands, usually mounted one to a car, through as many stands and/or carsas required for the full length of the rail-The car roller stands do notneed any height adjustment but just the rollers to facilitate themovement of the rail and act as storage racks until the train is movedto the track laying position where the rails are just pulled out oftheir storage position.

In yard storage a more compact storage pile is necessary and the railsare stored close together laterally with possibly 25 rails to one layerand with only conventional railroad ties separating each layer. Theremay be as many as five layers to a single storage pile. This means ofstorage proves desirable and economical where the laying of the newtrack is done quicker than the rail is welded and the rail must beaccumulated. It is in this type of application where the presentinvention is normally used.

SUMMARY OF THE INVENTION This invention provides in a simple, portableunit a means to safely raise a heavy, elongated object several inches byhand and to move the object to a desired position when the desiredelevation is obtained, with little resistance, by means of itsself-contained rollers.

One object of this invention is to provide a hand operated elevatingunit capable of small increments of adjustment and which may be quicklylowered when desired.

Another object of this invention is to provide a simple hoist unitequipped with a roller on which the object rests.

A further object is to provide a low silhouette hoist unit capable ofbeing placed under railroad rails and lower in overall height thanstandard railroad ties.

Another object is to provide a roller equipped hand operated hoist unitthat is light enough to be portable for easy movement to a new location.

Still another object is to provide a self-contained portable multipleroller stand which may be operated from one end of the unit for handlingobjects like welded railroad rail which will readily assist placing therail in closely spaced, multilayer storage piles.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings whichform a part of this specification and in which like reference charactersdesignate like parts in all ofthe views:

FIG. 1 is a perspective view of two of the lift roller standards of thepresent invention being used under three rails.

FIG. 2 is an end elevational view of the lift roller stand of FIG. 1.

FIG. 3 is a plan view of the lift roller stand of FIG. 1.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3.

FIG. 5 is a section taken along line 5-5 of FIG. 3 with the roller inits lowermost position.

' FIG. 6 IS a section similar to FIG. 5 but showing the roller in itshighest position.

FIG. 7 is a section taken along line 7-7 of FIG. 2 with the rollerrotated 90 to illustrate the eccentricity of the shaft.

DETAILED DESCRIPTION OF THE INVENTION In the embodiment of thisinvention as shown in FIGS. 2--4 the lift roller stand 8 is composed ofa base 10 having two long carrying handles 11 and 12 parallel to thelongitudinal axis of the base, two aligned pivot bearings 13 secured tothe base to form a part thereof and located transversely to one side ofthe longitudinal centerline of the base on the opposite ends of thebase, and a pair of pawl steps 14, each of which is formed on anextension 13a of one of the bearings 13. A lever assembly I5 ispivotally mounted in each pivot bearing I3 on a stub shaft 16 at eachend of the base, each lever being movable from thelowered position ofFIG. 5 to the raised position of FIG. 6 to raise and lower three centerrollers 9 (FIG. 1). Each stub shaft is retained in a pivot bearing 13 bya setscrew l7, and by a dowel pin 18 in the end of the shaft outside ofa lever plate 22 which forms a part of the lever assembly 15. The twolever assemblies are rigidly connected by two torque tubes 19 and 20that are joined together by a torque equalizing coupling 21 so that bothlever assemblies. each of which is welded to one of the torque tubes,.rotate together when operated from only one end.

As shown in FIG. 3, the torque tube 19 is provided with a pin 32 weldedto the tube adjacent its end opposite the lever assembly. Both ends ofthis pin project beyond the outside of the torque tube, and the axis ofthe pin is located approximately 10 from the vertical axis when thelever assembly connected to tube 19 is in its lowest position. Torquetube 20 is provided with a drilled hole adjacent its end that isopposite the other lever assembly, the hole being disposed approximately15 from the vertical axis when the lever is in its lowest position.Coupling 21, which fits over the ends of tubes 19 and 20, is providedwith a slot in one of its ends to receive the pin 32 and with a drilledhole that has a nut 33 welded centrally thereover on one outer surfaceadjacent the opposite end of the coupling. Both the slot and the hole inthe coupling are in alignment on the couplings longitudinal axis. Inassembly, the coupling 21 is slipped over the end of tube 19 so the slotengages the pin 32. The torque tube 20 is then slipped into thecoupling. The lever assembly connected to tube 20 is then rotatedslightly to overcome the 5 misalignment of the hole in the coupling andthe hole in the torque tube 20 so that threaded pin 34 may be insertedthrough the aligned holes to engage the nut 33 on the coupling. Theslight twisting to align the holes effectively pretorques the tubes sothat both lever assemblies will move in unison and have no lost motion.After the coupling is assembled to the torque tubes, the entire assemblymay then be lowered so that sideplates 22 and 23 of each lever are onopposite sides of one of the pivot bearings 13, and the pivot shafts 16are then inserted.

I The two lever assemblies l5. as shown in FIGS. 3, 5 and 7, areessentially identical except that they are right and left hand' 'andonly one lever has a backstop. They are made up of the two side plates22 and 23 with aligned holes 24 therethrough on one end to receive thestub shafts 16, two spacer plates 25 and 26 secured between the plates22 and 23 and'providing an opening 27, and a cylindrical bushing 28sccuredin aligned holes on the opposite end of the lever assembly, saidbushing passing through both plates 22 and 23. Spacer plate 26 also hasa foot portion 29 extending to the base on their extreme end to form astop that determines the lowermost position for the pivotal leverassembly 15. On the inner side of the lever assembly, a hub 30 is weldedto the plate 23, having its bore 31 concentric with bushing 28. Alubrication fitting 43 is provided, as shown in FIG. 3, in the hubforlubricating a bearing 47 that is disposed inside the hub 30.

As shown in FIGS. 5 and 6, a pawl 35 which is disposed in the opening 27in the lever has a hub 35a with a large bore 36, which freely receivesthe outside of bushing 28. A foot 37 extends from hub 35a and cooperateswith the pawl steps 14. In the lower end of each pawl, a hole 38 isdrilled, and a rod 39 is inserted connecting both pawls so they work inunison. The rod 39 is retained in the pawl by a setscrew 40. The footend of the pawl 37 rests on one of the pawl steps 14 and provides thenecessary rigid support for the associated pivoted lever assembly 15. Alubrication fitting 41 is provided in the top surface of pawl 35.

A roller shaft assembly 45 includes a composite shaft 46 (FIG. 7) andthe three rollers 9, as shown in FIG. 3. The shaft 46 includes two shortshafts 46a one of which is journaled at each end of the shaft assemblyin a bearing 47 which is sup ported in the bore 31 of hub 30. Each shortshaft 46a is machined with a cylindrical eccentric section 49, and asleeve 50 is welded to the two cylindrical eccentric sections 49, whenthe axes of the sections are in alignment, thus forming a unitaryshaftassembly with the sleeve 50 and the two sections 49 defining a singleeccentric section of shaft 46. The rollers 9 have a lubricating fitting42 and rotate freely on a greaseluhricated hardened surface 48 of thesleeve 50. Each roller 9 is equipped with at least one flange on itsouter surface to guide and retain the object handled. Shaft 46 alsocontains a square-ended extension 51 on one end on which a large ratchetwrench 52 (FIG. I) or other means may be mounted for rotating the shaftassembly.

As shown in FIGS.=,2, 3 and 7, a manually reversible backstop mechanism55 is mounted on the outer side of 'sideplate 22 of the lever assembly15 that has the drive shaft extension 51. Capscrews 56 are threaded intothreaded holes 57 in the spacer plates 25 and 26 to retain thismechanism in place. ,This backstop unit is concentric with the bearings,pawls and drive extension and operates on the square ended portion SI ofthe shaft 46. In the embodiment shown, the backstop is a ratchet typeclutch with a reversing feature which permits small increments of shaftrotation and locks against reverse travel when set for operation in oneposition, such as clockwise rotation. One ratchet clutch has been foundsuitable for this type of installation; a unit marketed by the LowellCorporation of Worcester, Mass. under the designation model 74. Such aclutch permits freewheeling in the forward clockwise direction, if theload imposed is sufficient as when the eccentric shaft goes over its topdead center position. When the reverse lever is operated, the reverseoperation results and shaft may rotate in the counterclockwise positionwhile locking in the clockwise direction.

" In FIG. 1, the lift roller stands 8 are shown in position to unloadthe last layer of rails R from a storage pile. The lever assemblies 15have actuated to move the roller shaft assembly 45 and the rollers 9 totheir lowermost position under the rails, with the pawls 35 on theirlowest steps, and the shaft 46 rotated so that the shaft eccentricity isbelow the centerline of the bearing bore in the lever assembly. Thisposition is shown in FIG. 5. The roller shaft assembly 45 is thenmanually lifted by rotating the lever assemblies 15 counterclockwise. asshown in FIGS. 2 and 6to' rrio ve the rollers 9 as close to the bottomof the rails as the pawl engagement with the pawl steps allows. Thebackstop is then engaged for clockwise rotation. and the ratchet wrench52 placed on the drive extension shaft. The wrench 52 normally has ahandle length of 36 inches to 42 inches in order to obtain sufficienttorque .by hand to lift the three rails. The wrench is the-n oper'atedclockwise, causing the eccentric shaft to rotate clockwise in smallincrements thereby raising the rollers 9 andtlie'rails thereon. Therollers are raised until the rails clear all the supporting ties. Therails may then be rolled out of the storage-pile. If this had occurredon an upper layer of the storage pile, the stands 8 would be moved,after the rails of the upper layerand ties supporting the upper layerhave been removed and replaced under the next layer of rails. Thisprocess is continued until the last layer of rails is removed.

When rails are moved into storage and a storage pile started a slightlydifferent routine is followed. The ties and the lift roller stands areplaced along the ground level at approximately 35 foot spacings. Theunloaded roller shaft assembly is manually lifted to a position so thatthe top of the rollers are higher than the ties being used. This is doneby pivoting the lever assembled l5 and letting the pawls 35 dropinto thedesired higher step. The" eccentric shaft is then rotated clockwise tonear its top dead centersppsition. This arrangement is illustrated inFIG. 6. After threerails are in position on top of the three rollers,the unit is readytolower the three rails to the top of the ties.Normally the rails are lowered'by rotating the eccentric shaft clockwisewith ,the backstop set for clockwise operation. This raises the railsuntil the eccentric point goes over center. As further rotation ,of theshaftstarts, the gravity weight will take over and overrunthe backstopor free wheeling results. The rails quickly drop to the top of-the ties.The stands are pulled out from under these railsand then placed on topof this layer of rails. Ties are placed alongside of the stands. Theprocess can then be repeated for another layer of rails and so continueduntil the desired height of rails is reached.

It is also possible to raise the lever and roller shaft assembly bymeans of the wrench and take advantage of the backstop action. To raisethe roller shaft, the lever assembly rotates in a counterclockwisedirection about its pivot bearing. The backstop unit is set forcounterclockwise rotation while the ratchet wrench is operated in theopposite or clockwise direction. The resulting motion, with the rollershaft locked, causes the lever assembly to rotate upwardly about itspivot axis lifting the pawls. The freely hanging pawls swing by gravityunder the roller shaft and climb up the pawl steps one at a time as highas desired, resting on the highest desired step when the wrench rotationis stopped. In this position it again rigidly supports the roller shaftassembly.

If it is desired to lower the lever assembly without load on therollers, the pawls are pushed off the pawl steps dropping the leverassembly with the roller shaft to the next lower steps. This action isassisted by the rod connecting the two pawls so that both pawls worksimultaneously.

In one embodiment of this invention, the rollers are each 4% inches indiameter by 7% inches long with a 5 7 8 inches diameter single flange onthe end rollers and a double flange on the center roller. As shown inFIGS. 5 and 6, the shaft has an eccentricity E of A nches, thus giving atotal lift of 1 inch and the four pawl positions provide a change inheight of 1 5/16 inches between H, andH The top of the roller in itslowest position is 5% inches above the bottom of the base, while the topof the roller in its highest position would be 7 7/16 inches above thebase, thus giving a maximum height variation of 2 5/16 inches. The unitis approximately 31% inches long with three rollers and 13 inches wideover the two handles.

In another embodiment of thejnvention the lever assembly is arrangedwith a hand operated, pivoted hydraulic jack or a small double actingcylinder connected to a closed circuit k i i hydraulic system equippedwith a hand pump. The roller assembly can then be raised and loweredunder the assistance of hydraulic power alone and the backstop, theeccentricity on the shaft and the ratchet wrench may be eliminated.

in a further embodiment of the invention, a rotary hydraulic cylindercapable of reciprocating through approximately 210 of arc and equippedwith a closed circuit hydraulic system having a hand pump may be used onthe shaft extension in lieu of a ratchet type wrench and the backstop onthe lever assembly may be eliminated.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described. it will be apparent thatmodifications and variation may be made without departing from what isregarded to be the subject matter of the invention.

lclaim:

l. A lift stand comprising:

a. a base;

b. lever means pivoted on said base;

0. article contacting roller means carried by said lever means at apoint spaced from the pivot axis of said lever means; I a

d. a rotary lift mechanism operatively connected between said rollermeans and said lever means for elevating said roller means to raise anarticle thereon; and

e. abutment means associated with said lever means and engaging saidbase to transmit the load on said roller means to said base duringactuation of said rotary lift mechanism.

2. A stand according to claim 1 wherein said rotary lift mechanismincludes a rotary ratcheting drive mechanism.

3. A stand according to claim 1 wherein said abutment means comprises apawl mounted for movement with said lever means.

4. A lift stand comprising:

a. a base;

b. lever means pivoted on said base;

c. article contacting roller means carried by said lever means at apoint spaced from the pivot axis of said lever means;

d. abutment means operably connected between said base and said levermeans to hold said lever means in a preliminary position wherein saidroller is raised to a predetermined position above said base; and

e. rotatable actuating means disposed inside said roller. and

anchored in said lever means for raising said roller above saidpredetermined position to elevate an article in contact therewith. 5. Alift stand according to claim 4 wherein said abutment means comprises ashaft journaled for rotation in said spaced.

levers and having an intermediate eccentric portion carrying saidarticle contacting roller.

7. A lift roller stand comprising the combination of:

a. an elongate base, a support on said base adjacent each longitudinalend thereof located transversely to one side of the longitudinalcenterline of the base;

b. a pair of lever assemblies, each assembly being mounted at one of itsends in a support and having a foot projecting downwardly from itsopposite end resting on said base;

c. a shaft rotatably supported in the lever assemblies at the lever endopposite the associated support, said shaft havf. means for rotatingsaid shaft whereby the roller is raised or lowered by the eccentricsection of the shaft as said shaft is rotated.

8. A lift roller stand as in claim 7 wherein said means for 5 rotatingthe shaft comprises a ratchet'type hand wrench whereby short incrementsof rotation may be readily made with the load held by the backstop andthe wrench handle may be located at any convenient angle.

9. A lift roller stand as in claim 7 wherein the backstop means is areversible ratchet type clutch. whereby the clutch will permit smallincrements of shaft rotation in one direction but prevent motion in theopposite direction until a control lever is manually repositionedreversing the-action.

10. A low profile hand operated hoist unit with a load supportingroller. the combination which comprises:

a. an elongate base, a pivot bearing adjacent each longitudinal end ofsaid base located transversely to one side of the longitudinalcenterline of said base. each bearing having pawl steps;

b. a lever assembly pivotally mounted at one of its ends in each of thepivot bearings;

c. a shaft rotatably mounted in the lever assemblies at the end oppositethe pivot bearings and having a drive extension protruding outside ofone lever assembly concentric with the axis of rotation of said shaftand having an eccentric section between the lever assemblies;

d. a pawl pivotally supported on each ofsaid lever assemblies concentricwith said rotatable shaft and having a foot portion cooperating with thepawl steps in said base, whereby the shaft height above the base may bemanually varied depending upon the pawl step engaged by the pawl as thelever assembly is pivoted;

e. a roller rotatably mounted on the eccentric section of said shaft;

f. backstop means mounted on the outer side of one lever assemblycooperating with the drive extension; and

g. a ratchet wrench attached to said drive extension for rotating saidshaft, whereby the roller is raised or lowered by the eccentric sectionof the shaft as it is rotated.

11. A hoist unit as in claim 10 wherein a rod connects said foot portionof the pawls, whereby the pawls move in unison in both upward anddownward directions.

12. A hoist unit as in claim 11 wherein when said backstop is lockedagainst clockwise movement of the shaft and said i ratchet wrench isrotated in the clockwise direction, the lever ing a drive extensionprotruding outside one of the lever with the assistance of the wrenchabove that obtainable by the' eccentric action of the shaft rotationalone.

13. A portable load lifting unit equipped with a roller the combinationcomprising:

a. an elongate base, a pivot bearing mounted adjacent each longitudinalend of said base and located transversely to one side of thelongitudinal centerline of said base, pawl steps formed on each pivotbearing;

b. A pair of lever assemblies, each assembly being pivotally mounted atone of its ends in one of said pivot bearings;

torque equalizing means connecting the pair of lever assemblies, wherebyeach lever assembly moves in unison with the other as the leverassemblies are pivoted;

d. a shaft rotatably mounted in each of the lever assemblies at thelever and opposite the associated pivot bearing and having a driveextension protruding outside of one lever assembly concentric with theaxis of said shaft and having an eccentric section between said leverassemblies;

e. a pawl pivotally mounted on each of said lever assembliesconcentrically with the axis of said shaft and cooperating with the pawlsteps in said base;

f. a roller rotatably mounted on the eccentric section of the shaft; and

g. means for rotating the shaft.

14 A load lifting unit as in claim 13 wherein the torque equalizingmeans for connecting the lever assemblies further comprises:

a. a first torque tube attached to the lever assembly adjacent thedriveextension;

b. a pin secured in said first torque tube adjacent the tube endoppositethe lever assembly and projecting beyond the outer surface ofthe torque tube;

. a second torque tube attached to the other lever assembly and having aradial hole therethrough adjacent the opposite end of said second torquetube, the radial plane of said hole being displaced about about from theradial plane of the pin in said first torque tube when the leverassemblies are in alignment;

d a cylindrical coupling mounted over the adjoining ends of a threadedpin inserted through the hole in the coupling and the hole in the secondtorque tube and engaging the threaded nut when said second torquet ubeis rotated upwardly about 5, whereby the torque tubes are placed underan initial torque.

1. A lift stand comprising: a. a base; b. lever means pivoted on saidbase; c. article contacting roller means carried by said lever means ata point spaced from the pivot axis of said lever means; d. a rotary liftmechanism operatively connected between said roller means and said levermeans for elevating said roller means to raise an article thereon; ande. abutment means associated with said lever means and engaging saidbase to transmit the load on said roller means to said base duringactuation of said rotary lift mechanism.
 2. A stand according to claim 1wherein said rotary lift mechanism includes a rotary ratcheting drivemechanism.
 3. A stand according to claim 1 wherein said abutment meanscomprises a pawl mounted for movement with said lever means.
 4. A liftstand comprising: a. a base; b. lever means pivoted on said base; c.article contacting roller means carried by said lever means at a pointspaced from the pivot axis of said lever means; d. abutment meansoperably connected between said base and said lever means to hold saidlever means in a preliminary position wherein said roller is raised to apredetermined position above said base; and e. rotatable actuating meansdisposed inside said roller and anchored in said levEr means for raisingsaid roller above said predetermined position to elevate an article incontact therewith.
 5. A lift stand according to claim 4 wherein saidabutment means comprises a stepped bearing member, secured to andforming a part of said base, and a pivoted pawl movable with the end ofsaid lever that carries said roller.
 6. A lift stand according to claim4 wherein said lever means includes a pair of spaced levers and saidrotatable actuating means comprises a shaft journaled for rotation insaid spaced levers and having an intermediate eccentric portion carryingsaid article contacting roller.
 7. A lift roller stand comprising thecombination of: a. an elongate base, a support on said base adjacenteach longitudinal end thereof located transversely to one side of thelongitudinal centerline of the base; b. a pair of lever assemblies, eachassembly being mounted at one of its ends in a support and having a footprojecting downwardly from its opposite end resting on said base; c. ashaft rotatably supported in the lever assemblies at the lever endopposite the associated support, said shaft having a drive extensionprotruding outside one of the lever assemblies and having an eccentricsection between the lever assemblies; d. a roller rotatably supported onthe eccentric section of said shaft; e. backstop means mounted on theouter side of said one lever assembly cooperating with said driveextension; and f. means for rotating said shaft whereby the roller israised or lowered by the eccentric section of the shaft as said shaft isrotated.
 8. A lift roller stand as in claim 7 wherein said means forrotating the shaft comprises a ratchet type hand wrench whereby shortincrements of rotation may be readily made with the load held by thebackstop and the wrench handle may be located at any convenient angle.9. A lift roller stand as in claim 7 wherein the backstop means is areversible ratchet type clutch, whereby the clutch will permit smallincrements of shaft rotation in one direction but prevent motion in theopposite direction until a control lever is manually repositionedreversing the action.
 10. A low profile hand operated hoist unit with aload supporting roller, the combination which comprises: a. an elongatebase, a pivot bearing adjacent each longitudinal end of said baselocated transversely to one side of the longitudinal centerline of saidbase, each bearing having pawl steps; b. a lever assembly pivotallymounted at one of its ends in each of the pivot bearings; c. a shaftrotatably mounted in the lever assemblies at the end opposite the pivotbearings and having a drive extension protruding outside of one leverassembly concentric with the axis of rotation of said shaft and havingan eccentric section between the lever assemblies; d. a pawl pivotallysupported on each of said lever assemblies concentric with saidrotatable shaft and having a foot portion cooperating with the pawlsteps in said base, whereby the shaft height above the base may bemanually varied depending upon the pawl step engaged by the pawl as thelever assembly is pivoted; e. a roller rotatably mounted on theeccentric section of said shaft; f. backstop means mounted on the outerside of one lever assembly cooperating with the drive extension; and g.a ratchet wrench attached to said drive extension for rotating saidshaft, whereby the roller is raised or lowered by the eccentric sectionof the shaft as it is rotated.
 11. A hoist unit as in claim 10 wherein arod connects said foot portion of the pawls, whereby the pawls move inunison in both upward and downward directions.
 12. A hoist unit as inclaim 11 wherein when said backstop is locked against clockwise movementof the shaft and said ratchet wrench is rotated in the clockwisedirection, the lever assemblies pivot upwardly in a counterclockwisedirection raising the shaft and permitting the pawls to seat on higherpawl steps, whereby the roller height may be varied under load with theassistance of the wrench above that obtainable by the eccentric actionof the shaft rotation alone.
 13. A portable load lifting unit equippedwith a roller the combination comprising: a. an elongate base, a pivotbearing mounted adjacent each longitudinal end of said base and locatedtransversely to one side of the longitudinal centerline of said base,pawl steps formed on each pivot bearing; b. A pair of lever assemblies,each assembly being pivotally mounted at one of its ends in one of saidpivot bearings; c. torque equalizing means connecting the pair of leverassemblies, whereby each lever assembly moves in unison with the otheras the lever assemblies are pivoted; d. a shaft rotatably mounted ineach of the lever assemblies at the lever and opposite the associatedpivot bearing and having a drive extension protruding outside of onelever assembly concentric with the axis of said shaft and having aneccentric section between said lever assemblies; e. a pawl pivotallymounted on each of said lever assemblies concentrically with the axis ofsaid shaft and cooperating with the pawl steps in said base; f. a rollerrotatably mounted on the eccentric section of the shaft; and g. meansfor rotating the shaft.
 14. A load lifting unit as in claim 13 whereinthe torque equalizing means for connecting the lever assemblies furthercomprises: a. a first torque tube attached to the lever assemblyadjacent the drive extension; b. a pin secured in said first torque tubeadjacent the tube end opposite the lever assembly and projecting beyondthe outer surface of the torque tube; c. a second torque tube attachedto the other lever assembly and having a radial hole therethroughadjacent the opposite end of said second torque tube, the radial planeof said hole being displaced about about 5* from the radial plane of thepin in said first torque tube when the lever assemblies are inalignment; d. a cylindrical coupling mounted over the adjoining ends ofsaid torque tubes having a slot in one end matingly engaging theprojecting ends of the pin in the first torque tube and having a holetherethrough having a nut concentrically attached above the hole in theopposite end of said coupling in alignment longitudinally of thecoupling with the slot; and e. a threaded pin inserted through the holein the coupling and the hole in the second torque tube and engaging thethreaded nut when said second torque tube is rotated upwardly about 5*,whereby the torque tubes are placed under an initial torque.